A family steeped in Corot uses connoisseurship and instinct to distinguish the real paintings from copies and fakes
Back in 1953, ARTnews reported on the French saying that “Corot painted 2,000 canvases, 5,000 of which are in America.” While this is an obvious exaggeration, it is well known that—as the world’s leading Corot scholar, Martin Dieterle, puts it—Corot “has the distinction of being the most frequently forged painter in history.”Just how many Corots were actually painted by Corot? Dieterle, 77, has been pondering this question for decades. In his office in a modest town house on a tree-lined cobblestone passage in central Paris, he has been working with his stepdaughter, Claire Lebeau, to update a computer databank they have been compiling for two decades that catalogues all Corot’s paintings as well as every known copy or fake they have ever come across.Dieterle is a fifth-generation Corot expert: Jules Dieterle, his great-great-grandfather, was one of the painter’s most intimate associates. His great-grandfather, Charles Dieterle, spent a decade in Corot’s atelier as a student and factotum; Charles’s wife, Marie Dieterle, a successful landscape and cattle painter, was also the artist’s close friend. Martin’s grandfather, Jean Dieterle, annotated the catalogue raisonné of Corot’s work, and his father, Pierre, was also a renowned Corot scholar.Today, Dieterle and Lebeau receive requests from all over the world to examine and authenticate artworks—more than l00 in the first six weeks of 2012. They have already classified more than half of those works as fakes, while some 20 “maybes” are still under consideration. In general, they say, about 80 percent or more of the works they examine are not original Corots.Corot (1796–1875) was extremely prolific: he produced some 3,000 paintings and roughly the same number of drawings, Dieterle says. Even today, real Corots still come to light “in someone’s attic or basement, at a flea market or estate sale.”Dieterle and Lebeau deliberate and debate the qualities of each work submitted to them, often bringing in other specialists. The decision to validate a work, Dieterle says, rests on three elements. First is “a sense of responsibility” to the artist. Next is an evaluation of the documentary evidence (letters, notes on provenance, invoices, or other sources). Finally, he says, there is an intuition that arises from an intimate knowledge of the artist developed over several decades. As he puts it in French, the feeling is “en notre âme et conscience”—in the soul and the mind. “With certain works,” he says, “we’ll know right away if it’s original or not. For others, we have to go deeper.” Their opinions often evolve over time; it’s not unusual for them to live with a work for a year or more before offering their expertise.“It doesn’t matter if there’s a scientific dossier several inches thick,” Dieterle adds. “It’s purely mental, a reflection of the soul. That’s part of our criteria. If it doesn’t swing, if it doesn’t dance, it’s not Corot.”Dieterle’s devotion to Corot began in his childhood. A Corot painting hung at the foot of his bed. From his grandfather, who died in 1971, he learned to love all painting, “modern, contemporary, classic, primitive. He was a charming man, the only real gentleman I ever met. He and my father slowly injected me with a certain way of looking.” Dieterle also brings an artist’s eye to his work. He is a painter, trained at the famous École Boulle in Paris, where he also learned the science of art materials, and he spent several years working with chemists and art-supply manufacturers in France and Belgium. Throughout his life, he visited his grandfather and father regularly, helping them compile their catalogue. Dieterle officially took over the work on Corot full time in 1982, when his father, then 75, admitted he was getting too old to continue alone. Profoundly knowledgeable about Corot’s life, Dieterle is also sensitive to the poetic quality he finds in the work. He explains that Corot grew up not long after the worst phase of the French Revolution, the Reign of Terror of 1793–94. He was sent away from home with a nursemaid when he was two years old and then placed in a succession of boarding schools. “So, in a sense, he felt like an orphan,” says Dieterle. “His youngest years seem to have been very lonely. You can sense the tenderness in his paintings of children and of women.” Dieterle also mentions Corot’s mother, a successful milliner, in connection with the grace and balance in his work. “He was incapable of making anything clumsy,” he says.Corot died a bachelor, without known heirs, “but it’s obvious that he loved women,” Dieterle says. “His painting tells us he was a profoundly sensual being. One could say that Corot has the most powerfully sensual ‘handwriting’ in the 19th century, in terms of line and imagination, and that sensuality can be found not only in a woman, but in a forest, rocks, or a river.” Pointing to an 1828 landscape, Dieterle says, “I never saw a waterfall so ‘edible’, so voluptuous. It’s absolute pure poetry.”The research of Dieterle and Lebeau rests on Alfred Robaut’s catalogue raisonné, published in four volumes by Floury in 1905. Robaut started the catalogue around 1867, so he worked on it for less than a decade before the artist’s death in 1875. Etienne Moreau-Nélaton took over the work in 1898 and brought it to conclusion. “In the catalogue,” says Dieterle, “2,460 paintings are identified, inventoried, catalogued, and annotated—the work of a titan.”For a time, the catalogue was believed to be virtually complete. Robaut had worked with Corot’s collectors and important dealers, including English dealers who sold to Americans. Dieterle’s great-grandfather and grandfather, who also published much of Corot’s archive, accumulated and consolidated the information. After Robaut’s death, dealers and experts asked them to continue the work.In 1948, the first supplement to the catalogue raisonné was published, by Jean Dieterle and André Schoeller. It presented an additional 100 canvases that Robaut had been unable to account for. According to Dieterle, there were several reasons why these pictures were difficult to track down.One was Corot’s well-documented generosity. In 1868, for instance, when his friend Daumier, unable to pay his rent, was about to be evicted, Corot bought his small house in Valmondois and gave it to him. Corot donated most of his wealth to the Visitandine Sisters for an orphanage; and, “sweet, gentle, and modest to a fault,” according to Dieterle, he also gave part of his wealth to friends. Most important, he gave many of his canvases to friends, but no records of these gifts exist.Dieterle says it isn’t true that Corot authorized friends, pupils, or poor artists to sign his name to canvases in his style, or even that he signed them himself, so they would be easier to sell. Only one such incident is documented, he says. A poor artist came to Corot’s studio one day, asking for help to feed his family and pleading with the master to sign his painting. Corot took the canvas into his atelier and asked the poor artist to return the next day, then spent an entire afternoon reworking the canvas before signing it.But Corot left his paintings with friends while he was traveling or lent them to people. “He would go to my great-great-grandfather’s home on the Normandy coast, where they painted together,” Dieterle says. “But if, for instance, Corot wanted to continue on to Brittany, taking along the wet canvases was bothersome, so he would leave them for safekeeping. Or if a friend asked to make a copy, he would always lend him the painting, but some were never returned.” America was another source of paintings not inventoried by Robaut. Wealthy Americans were among Corot’s first collectors. “Some of these paintings were purchased 20 years before Robaut became involved with Corot,” Dieterle says, “so he could never locate them. Often these painting had been purchased directly from Corot’s atelier, so it was impossible for Robaut to have known about them.”Dieterle and Lebeau don’t need a laboratory outfitted with state-of-the-art equipment, because most Corot copies were executed during the artist’s lifetime, thus eliminating the need for forensic authentication. Why were his works so often copied? Dieterle says that Corot is “on the cusp—at the end of classical painting and in the forefront of modern painting, alongside Turner, Constable, Courbet, Géricault, and Delacroix. Painting suddenly became gestural, so I think a lot of painters looked at Corot and thought it was simple. Everything that looks like a nice landscape, they would add his signature.” Corot became famous late in life, when he was already in his 60s. “Suddenly, dealers and collectors were lined up outside the studio,” says Dieterle. “For the first time, he found himself with a long list of requests for paintings, and poor painter-friends were all around him. So he got the idea to help them and himself by creating an atelier for producing works, often two or three paintings of the same motif, with just small variations.” In a sense, Dieterle says, a kind of “industry” of copies developed.As the demand for Corot’s paintings grew, the artist’s disciples and friends, as well as other artists painting in his style, began signing his name to their works. “Paradoxically,” says Dieterle, “we also find many real Corot paintings with fake signatures, because dealers would often sign them for clients.” There was even one specific expert at faking his signature. “Corot was not keen on signing his works. He signed when he gave away a painting, or when someone asked him to, but in general, when he was working in the landscape, it wasn’t a priority,” Dieterle says. He sometimes signed works 40 or 50 years after completing them; some of his Italian landscapes, for instance, had remained in his studio and he didn’t feel the need to sign them. “Fortunately, we know how to read Corot’s signature,” says Dieterle. “The handwriting is easy to imitate, but it’s become easy to recognize the fakes.”Dieterle and Lebeau are in the midst of preparing the sixth supplement to the artist’s catalogue raisonné (no publication date has yet been announced). They are also cataloguing Corot’s graphic works, with New York dealer Jill Newhouse, who Dieterle calls “one of the most gifted eyes in this matter.” Corot’s drawings are particularly difficult to identify because of the artist’s surprising range, from a precise, Ingres-esque virtuosity to a much looser tonal approach. The full stylistic range, from detailed linear drawings made in Italy in the 1820s to more abstract, volumetric works from the 1860s, will be on view in an exhibition Newhouse is organizing, with Dieterle and Lebeau, in her New York gallery (June 5 through July 13). The first show ever of Corot drawings in the United States, it will feature unpublished works from private American and European collections.Laurie Hurwitz is the Paris correspondent for ARTnews.